This invention relates to agents for and methods of processing synthetic fibers.
During the course of production and processing of synthetic fibers, an agent containing a lubricant and an antistatic agent is usually applied to them in order to provide them with lubricity and antistatic characteristic. When the synthetic fibers are subjected to a heat treatment or, for example, to a false twisting process, however, it is important to prevent the contamination of heaters due to the thermal degradation of such agent during the heat treatment and to thereby prevent the generation of fuzz and occurrence of yarn breakage and to obtain false-twisted yarns of a high quality. This invention relates to agents and methods with which such contamination of heaters can be effectively prevented.
As an agent for preventing such contamination of heaters, it has been known to use a mixture of a polyether compound, a polyorganosiloxane compound and an ionic surfactant. Examples of polyorganosiloxane compound which may be mixed in such a prior art agent include (1) polydimethyl siloxane and fluoroalkyl modified polydimethyl polysiloxane with viscosity at 25.degree. C. greater than 30.times.10.sup.-6 m.sup.2 /s and surface tension at 25.degree. C. less than 28 dyne/cm (See Japanese Patent Publication Tokkai 54-46923), (2) polydimethyl siloxane with viscosity at 30.degree. C. greater than 15.times.10.sup.-6 m.sup.2 /s (See Japanese Patent Publication Tokkai 48-53093), (3) phenyl polysiloxane with viscosity at 30.degree. C. in the range of 10.times.10.sup.-6 -80.times.10.sup.-6 m.sup.2 /s (Japanese Patent Publication Tokko 47-50657), (4) polyether modified polyorganosiloxane (U.S. Pat. Nos. 4,561,987 and 5,061,384), (5) linear polyorganosiloxane with 4-12 siloxane units (U.S. Pat. No. 5,772,910), and (6) ring-like polyorganosiloxane with 4-14 siloxane units (U.S. Pat. No. 5,755,984). With these prior art agents, however, contamination of heaters during a heat treatment cannot be prevented sufficiently. In the case of a false twisting process using short heaters of a recently developed kind for heat treatments at temperatures over 300.degree. C., in particular, the contamination of heaters could not be prevented satisfactorily. As explained above, if the contamination of heaters cannot be prevented to a satisfactory degree in the heat treatment process, fuzz and yarn breakage will take place and it is not possible to produce yarns with a high quality.